A four-door sedan was travelling eastbound on 71st Street when it collided with a Scion that was southbound on Calumet Avenue, Alfaro said.

A witness told a reporter at the scene that one of the vehicles involved in the crash sped through a stop sign and was being chased by police. Alfaro said the incident was not a police pursuit.

The Scion’s driver tried to run away from the scene of the crash on foot, but he was arrested by police and taken to Jackson Park Hospital in unknown condition, Alfaro said. His age was not immediately known.

Three male occupants of the sedan were taken to John H. Stroger Jr. Hospital of Cook County in critical condition, Alfaro said.